The acceleration of an electron by the ponderomotive force of a Gaussian whistler pulse in a magnetized high-density quantum plasma obeying Fermi–Dirac distribution is studied using the recently developed quantum hydrodynamic model. Effective acceleration takes place when the peak whistler amplitude exceeds a threshold value, and the whistler frequency is greater than the cyclotron frequency. The threshold amplitude decreases with ratio of plasma frequency to electron cyclotron frequency. The electron is accelerated at velocities of about twice the group velocity of the whistler.

The overview of the recent results for discovery and investigations of a very exotic phenomenon – optical mirage in the X-ray spectral range – is presented. It was found that the mirage could be created in the form of coherent virtual point source, emerging in the vicinity of the second plasma in two-stage oscillator-amplifier X-ray laser. The X-ray source-mirage, rigidly phased with the initial radiation of generator, occurs only when amplification takes place in the amplifier plasma and leads to the appearance of the interference pattern in the form of concentric rings in the spatial profile of the output X-ray laser beam. The equation describing the emergence of X-ray mirage was found, numerical solution of which shows that its formation is similar to that of the optical mirages observed at propagation of light rays through an inhomogeneously heated air. Obtained results have already demonstrated novel comprehension into the physical nature of amplification of X-ray radiation, opening additional opportunities for X-ray interferometry, holography, and other applications, which require multiple rigidly phased sources of coherent radiation.

The mass ablation rate and ablation pressure on laser-irradiated spherical microshells were measured using the space-resolved X-ray spectroscopy. A new method for the study of the ablation by means of the Doppler shifted X-ray images is proposed. The time-resolved measurements of X-ray emission from layered microtargets allow us to determine the heat front penetration through the microshell wall.

Possibilities are discussed of using Brillouin cells to produce high-peak-power radiation with the diffraction-limited divergence. The major emphasis is on the problems of coherent beam coupling at the output of several optical channels and of laser-pulse compression.

The characteristics of a laser plasma created by a high intensity UV excimer laser were investigated. The UV laser plasma was used as a switch for control of the laser pulse duration for the first time. An X-ray preionized XeCl laser pulse duration can be changed from 10 to 85 ns. This technique is useful for many applications of excimer lasers requiring various pulse durations.

The transmitted and reflected second harmonics (SH) generation by an oblique p-polarized laser pulse irradiated on vacuum-magnetized plasma interface is investigated. The laser pulse propagates through a homogenous, underdense, and transversely magnetized plasma. The transverse magnetic field plays the role of a self-generated magnetic field produced in laser plasma interaction. It is shown that if the transmitted and reflected SH components investigated as a simultaneous process, the maximum SH power deviates from previous reports specially near the critical angle. The deviation increases with laser field intensity and plasma density. The results reveal that the conversion efficiency increases slightly by increasing incident angle and drastically enhances near the critical angle. We show that the transmitted SH power decreases by increasing the magnetic field strength, in contrast to the normal incidence, which the SH power is increased. The comparison revealed that the SH efficiency is greater for transmitted component, while the reflected component is more proper for technical and experimental applications. This paper not only conforms the previous reports for angle far from the critical but also modifies them for the SH generation near the critical angle. Moreover, this paper gives a new insight for SH generation by a magnetized plasma.

Experimental results are reported on an extractor for pulsed, high-intensity beams of intermediate mass ions. Aluminum and indium plasmas were generated using a metal vapor vacuum arc. A method for electrostatic separation of ions from electrons at the anode was utilized to generate constant current beams, insensitive to plasma flux variations.

A maximum extraction voltage of 30 kV was applied across a 1·6 cm gap. Voltage pulse length ranged from 10 to 50μsec. Peak current densities of 15 mA/cm2 and normalized emittance of εn<3χ10-7; π-m-rad were achieved for Al+ and In+ from a 20-cm2 anode. Ions were predominantly in the +1 ionization state with no observable species contamination. The technology may have application to the induction linac approach to Accelerator Inertial Fusion.

The effects of finite bandwidth and random-phase pumping on parametric instabilities have been studied extensively (Thomson & Karush 1974; Thomson 1975; Laval et al. 1977). The possibilities arising from the use of this method and a time delay to obtain a spatial incoherence uniform illumination have been proven in experiments (Lehmberg & Obenschain 1983; Mima & Kato 1982; Kato & Mima 1982; Richardson 1981). In this paper we investigate this subject in an alternative way and obtain some results on the influence of the gain profile on parametric instabilities.

At the installation SOM, the experimental study of the impulse acceleration influence on the behavior of the turbulized layer obtained as a result of Rayleigh–Taylor instability (RTI) action on the system of two different density liquids with the density ratio n = 3, has been performed. After application of impulse acceleration the systems were moving according to inertia, and by using the light method the coordinates of penetration of the heavier liquid into the lighter one and vice versa were determined. The liquids studied were placed inside the ampoule that had internal working sizes (54 × 64 × 120) mm3. There were initial accidental perturbations like a rough solid surface at the interface and the width of the initial perturbation zone was L0 = 2.3 mm. The moving ampoule blow against metal plates created the impulse acceleration. The relative impulse acceleration was δg/g11 = 22.2–66.6 where g11 is the ampoule acceleration before the impact, the impulse duration was varied from 0.27 ms to 0.096 ms. The results concerned with the turbulized layer extension after the impulse acceleration action were obtained.

Surface periodic structures are generated upon irradiation of a silicon carbide (SiC) thin film by the plasma produced by 40 fs pulses from a Ti:Sapphire laser focused onto a thick low density polyethylene (LDPE) foil facing the SiC film. Independently of the number of laser pulses applied, these structures, with average regular periodicity of 710 nm, are evident throughout all irradiated areas. We attribute their formation to the efficient coupling of the unfocused femtosecond laser pulse with the incoherent extreme ultraviolet component of the laser-generated LDPE plasma.

The Rayleigh—Taylor instability is studied by means of a slab model and when slab thickness D is comparable to the ablation-to-critical surface distance. Under these conditions the perturbations originating at the ablation front reach the critical surface, and in order to determine the instability growth rate, we must impose boundary conditions at the corona. Stabilization occurs for perturbation wave numbers such that kD ˜ 10.

We are developing neutron diagnostics to characterize the implosions performed with the Phebus laser, operating at 5 kJ blue light delivered in 1·3 ns. For measuring the glass pusher areal density, (ρΔR), of the target, a silicon radiochemistry diagnostic has been implemented and is currently being used. We describe the diagnostic and its performance. Pusher areal density measurements, (ρΔR) and calculated values of fuel density are given. Deuterium (D)-tritium (T) final densities as high as 100 × D-T liquid density (20 g/cm3) have been achieved.

In this article, we discuss the modifications that occur in the brightness and gain of a longitudinal wiggler-free electron laser with the aid of induced betatron oscillation. Two novel approaches have been discussed to improve the gain of the system. In the first scheme, an auxiliary undulator field with betatron oscillations brings in additional bunching and results in enhanced gain. In the second scheme, an axial magnetic field is tuned to provide additional bunching for gain enhancement.

A classical linear theory is used to compare large synchrotron sources to a rf linear accelerator employed as a VUV/X-ray source. Comparisons are made on a per-pulse basis. It is demonstrated that the linear accelerator as an X-ray source is comparable to large synchrotron accelerators with wiggler insertion devices at the experiment. Applications to lithography, X-ray microscopy, X-ray spectroscopy and detector calibration are examined. Excluding lithography, the linear accelerator with an appropriate laser source is a useful source of X rays for these applications. As verification, classical results are compared with quantum mechanical results and are shown to be in good agreement.

This paper elaborates the effect of unmatched stored energy in high-voltage high-energy pulsed power systems. High-voltage insulation failure of KALI system is analyzed thoroughly for its occurrence. According to the simulations and analysis energy mismatch of MARX generator and Blumlein transmission line is found to be the most significant cause for high-voltage failure of the system. MARX generator and Blumlein of KALI are redesigned to attain better energy balance at same voltage level. Observations, simulation and analytical results are illustrated in the following sections.

The use of the Soft X-ray Contact Microscopy technique is discussed as a possible new tool to get information on dopant distribution in the core of single-mode optical fibers with 50 nm spatial resolution.

1-D computer simulations have been performed to study the influence of X-rays preheating on the compression of spherical laser-produced plasmas. The targets are glass microballoons filled with Neon at the initial pressure 10 bars. It is assumed that the only significant absorption process in the Neon is by inverse bremsstrahlung absorption. The results indicate that the radiative preheating energy has a nonnegligible effect on the compression, and a study of the Lawson criterion shows that this effect is more important for high-Z target shell materials and for thicker shells.

The one-dimensional Lagrangian code MEDUSA has been adapted to model the pressure of laser photons and the transfer of laser light momentum to underdense plasma investigated using the modified code. It is shown for lasers of wavelength ≃ 1μm that the plasma electron density needs to be close to the critical density (1021cm−3) and that the laser intensity needs to be greater than ∼1016Wcm−2 for significant laser momentum transfer to plasma. It was found that small plasmas (scale-length = 1 μm) result in the best ‘signature’ of laser light momentum transfer to plasma (more enhanced expansion velocities) but that the largest momentum transfer is for the largest plasmas considered (scale-length = 100 μm). The formation of suitable underdense plasmas for momentum transfer by a laser pre-pulse onto a foil target is investigated using a two-dimensional Eulerian code.